snail mail

電子メール全盛の時代、電子メールがほとんど一瞬で届くのに対比して、通常郵便をかたつむりの鈍さに喩えて、snail mailとは甚だ失礼な表現のように思えます。

電子メール（e-mail）に対して、普通郵便（s-mail）と略されているそうです。

ちなみに、現代の普通郵便より遅いという意味でしょうか、"pony express"（馬による郵便配達）という表現も存在するようです。

Maddening waits. If you know what you want, electronic shopping is almost always faster than schlepping off to the store. If you don't, be prepared for incredibly tedious delays as you browse. While you can flip through a paper catalog in seconds, you'll feel your gums receding in the time it takes to load a few pages of fashion choices on a Web site at dial-up speeds. Limited payment options. If a site doesn't take credit cards, you're back in Snail Mail Country, moving from the speed of light to pony express. This is a particularly tough problem when you're trying to nail down a unique item at an auction site like eBay. Even if you're lucky enough to hold the high bid when the virtual gavel falls, you must make your purchase offline, either paying by check or money order (requiring a visit to the bank, located in the smelly old real world).